Php-rowspan在同一行显示数据库中的所有记录

rowspan有问题，它将数据库中的所有数据打印到一行中！ 即使是不同id的那个！ 输出应该是课程名称和所有参加该课程的学生，将我的代码仅用于数据库中的第一个课程名称，并将其与数据库中的所有学生名称一起打印出来

我的代码是

                      <h2> List of course Name with students names</h2>

<?php


        include('../connect.php');
        $id=$_SESSION['login_user'];


        $sql = "SELECT C.CourseName ,GROUP_CONCAT(s.Studntname) AS Studntname
                FROM course AS c
                INNER JOIN student AS s
                ON s.CourseID = c.CourseID"; 

        $result = mysql_query ($sql, $connection); 


          echo "<center>";

        echo "<table>";
        echo "<tr> <th>Course Name</th> <th> Student Name</th>  </tr>";

        // loop through results of database query, displaying them in the table
        while($row = mysql_fetch_array( $result )) {
                // echo out the contents of each row into a table
               echo "<tr>";

                echo '<td>' . $row['CourseName'] . '</td>';
                echo "<td rowspan='' >" .$row['Studentname'] . "</td>";


                echo "</tr>";


        }
        echo "</table>"; 
         echo "</center>";



?>

学生

Studentname var(30)
StudentID   int(7) 
CourseID    int(7)  

---

问题在于您的查询。您没有使用

分组依据

，这是指定聚合数据分组依据的列所必需的（因此命名）

当然，如果您需要列出没有人参加的课程，您必须使用

左连接

，而不是

内部连接

：

    $sql = "SELECT C.CourseName ,GROUP_CONCAT(s.Studntname) AS Studntname
            FROM course AS c
            LEFT JOIN student AS s ON s.CourseID = c.CourseID
            GROUP BY C.CourseName "; 

至于

rowspan=''

部分，我不明白这一点。没有道理。或者

• 不要把它放在那里，用普通的

• 如果需要单元格跨越多行，请使用正确的值，如

    $sql = "SELECT C.CourseName ,GROUP_CONCAT(s.Studntname) AS Studntname
            FROM course AS c
            INNER JOIN student AS s ON s.CourseID = c.CourseID
            GROUP BY C.CourseName "; 

    $sql = "SELECT C.CourseName ,GROUP_CONCAT(s.Studntname) AS Studntname
            FROM course AS c
            LEFT JOIN student AS s ON s.CourseID = c.CourseID
            GROUP BY C.CourseName ";